/**
 * Spawn an `opencode acp` (or any ACP-speaking) harness as a subprocess and adapt
 * its stdio to the {@link AcpTransport} port — ADR 0062, slice 2.
 *
 * This is the **only** module in the ACP backend that touches `node:child_process`:
 * the JSON-RPC peer and client speak solely to the transport port, so the whole
 * ingestion stack is exercisable in-memory (see `inMemoryTransportPair`) without a
 * live process. `initialize` still runs against a real `opencode acp` in the
 * env-gated integration test.
 */
import { type ChildProcessWithoutNullStreams } from "node:child_process";
import { type AcpTransport } from "./transport.ts";
export interface SpawnAcpOptions {
    /** The harness executable (e.g. `"opencode"`). */
    readonly command: string;
    /** Its arguments (e.g. `["acp"]`). */
    readonly args?: readonly string[];
    /** Working directory for the harness process. */
    readonly cwd?: string;
    /** Extra environment for the harness (merged over `process.env`). */
    readonly env?: Readonly<Record<string, string>>;
    /** Where to route the harness's stderr diagnostics. Default: drained and discarded. */
    readonly onStderr?: (chunk: string) => void;
}
/** An {@link AcpTransport} bound to a spawned harness, exposing the child handle. */
export interface SpawnedAcpTransport extends AcpTransport {
    /** The underlying child process (for lifecycle assertions / signals). */
    readonly child: ChildProcessWithoutNullStreams;
}
/**
 * Spawn the harness and return a transport over its stdin/stdout with ACP's
 * newline-delimited JSON framing. The child's stderr is protocol-irrelevant
 * (diagnostics only): it is always piped and routed to `onStderr` when provided,
 * otherwise drained and discarded (never inherited by the parent's stderr).
 */
export declare function spawnAcpTransport(options: SpawnAcpOptions): SpawnedAcpTransport;